Flow regulator for piston-equipped cylinder



2 Sheets-Sheet l mg? M Sept. 20,` 1966 A. B. NEWTON FLOW REGULATOR FORPISTON-EQUIPPED CYLINDER Filed Feb, l, 1963 Sept. Z0, 1966 A. B. NEWTONFLOW REGULATOR FOR PIfSTON'EQUIPPED CYLINDER 2 Sheets-Sheet 2 Filed Feb.1, 1963 U aww@ JQZ f t/ @vga/@ww ander 5 United States Patent 3,273,786FLOW REGULATR FR PISTON-EQUIPPED CYLINDER Alwin B. Newton, 136Shelbourne Drive, York, Pa. Filed Feb. 1, 1963, Ser. No. 255,491 4Claims. (Cl. 2311-23) This invention is a continuation-impart of mycopending application, Serial No. 760,995, filed September 15, 1958, nowpatent No. 3,076,593.

This invention relates to a flow regulator for a pistonequippedcylinder, and, more particularly, to a flow regulator for the gas intakeline for a compressor.

In certain applications of air conditioning, the compressor is operatedirrespective of whether refrigeration is called for. One prime example`is in automotive refrigeration. There, the compressor piston is`directly coupled to the crankshaft and reciproc-ates whetherrefrigeration is needed or not. This operation is currently justified,since automobiles are overpowered and the power utilized in therefrigeration -compressor does not seriously affect the engineperformance. It would be desirable, however, to provide means whichwould regulate the amount of compression effected by the compressor as afunction of the refrigeration load. It would further be desirable toprovide means to reduce the capacity of the compressor during periodswhen little or no compression is required. These, then, form some -ofthe objectives of this invention.

Another objective is to provide a novel flow regulator for apiston-equipped cylinder. Still another object is to provide means int-he gas intake to la piston-equipped cylinder that regulates the flowof gas thereto. Yet another object is to provide means cooperating withthe piston of a piston-equipped cylinder that regulates the degree ofcapacity or unloading of the cylinder and thereby correlates thecompression developed by the cyl inder to the load requirements.

A further object of the invention is to provide a novel structure of thecharacter indicated in which a flow fitting or port member is sealinglyand positionably mounted in the gas intake to a piston-equipped cylinderwith the piston being movable into engagement with the fitting or portto close the same. A still further object is to provide in the apparatusdescribed in the object immediately preceding, means for positioning thefitting or .port member which is responsive to a thermal signal. A yetfurther object is to provide, in the apparatus just described, timedelay means which postpones the imposition of all or part of the load onthe compressor until it has started up. `Other objects and advantages ofthis invention can be seen in the details of construction and operationset down in this specification.

This invention will be described in conjunction with the accompanyingdrawing, in which- FIG. 1 is a fragmentary elevational view, partly insection, of apparatus embodying the teachings of this invention;

FIG. 2 is a cross-sectional View, taken along the line 2-2 of FIG. 1;

FIG. 3 is a view similar to FIG. 1 but showing a plurality of cylindersin the inventive compressor;

FIG. 4 is Ia sectional View taken along the line 4-4 of FIG. 3;

FIG. 5 is a fragmentary sectional view of apparatus such as is seen inFIG. 3 and showing a modified form of controlling the positionableelement for varying the degree of unloading in the inventiveconstruction; and

FIG. 6 is a perspective view of the movable element of FIGS. 1 and 2.

In the illustration given in FIG. l, the numeral 10 designates generallya cylinder provided las part of a frame F which has a piston slidablymounted therein and which 3,273,786 Patented Sept.. 20, 1966 isreciprocated by a piston rod 12 coupled to piston 11 through a wrist pin13 in a conventional fashion.

The cylinder 10 is equipped with an outlet port .14 communicating withan outlet manifold 15, the manifold supporting an exhaust check valve16. The foregoing arrangement is well known, and therefore details havebeen omitted as unnecessary, i.e., spring mountings, etc. for checkvalves. An inlet check valve 17 is provided in conjunction with theinlet manifold 18, each of the check valves 16 and 17 operating inconjunction with 'a suitable port as at 14 -and 19, respectively.

The inlet manifold 18 is equipped with a second flow port 20 whichcommunicates with the interior of an integral supplemental housinggenerally designated 21. Slidably positioned within the supplementalhousing 21 is a flow fitting or element generally designated 22 andwhich functions in the invention to vary the degree of compressorloading. For this purpose, the element 22 is hollow as at 23 and isequipped with a notched-out bottom portion as at 24., conforming as at22a to the piston, i.e., being ground to the radius of the piston. Thus,the element 22 provides at least a portion of the cylinder wall.

From the foregoing, it will be seen that a path for the liow ofrefrigerant gas alternative to port 19 is provided via the port 20, thehollow interior 23 of the element 22, and the notched-out portion 24, soas to communicate with the head space 10a in the cylinder 10. In theposition of element 22 shown in FIG. l, the compressor is fully loaded,i.e., as the piston 11 rises, there is no return of the refrigerant gasto the intake manifold 18. However, the compressor can be fully unloadedby elevating the element 22 so that during the entire upstroke of thepiston 11, there is provided a by-pass around the inlet check valve 17.`In this connection, it is noted that the upper sur-face of the piston11 is relieved as at 11a to accommodate the inlet check valve 17.

The position of the element 22 is regulated by means of a solenoid 25.The solenoid acts against a coiled spring 26 interposed between the topwall 27 of the housing 2'1 and a spider 28 provided interiorly of theelement 22. Extending axially of the spring and into the solenoid 25, isa rod 29. Thus, as the solenoid is energized, the rod 29 is movedupwardly to the position designated 29 (in dotted line) to move theelement 22 to a position of unloading the cylinder 10. A suitable sealas at 30 may be interposed where the rod 29 extends upwardly outwardlyof the housing 21.

For the purpose of energizing the solenoid 25, an electrical circuit asat 31 may be employed which includes a switch 32 for manual operation, atime delay switch 33, and a thermostatic switch 34.

Operation In the operation of the apparatus just described, and inconjunction with an automobile refrigeration system, the intake manifold18 is connected to a condenser (not shown) while the outlet manifold 15is connected to the usual expansion valve and evaporator (also notshown). In such a case, the piston 11 is energized from the engine crankshaft through the piston rod 12. The manual and safety switch isprovided as part of the ignition switch, while the thermostat 34 isresponsive to the temperature within the passenger space of theautomobile. When the automobile is started, switch 32 is closed, alongwith the time-delay switch 33. If the thermostatic switch 34 is in theposition shown, this will energize solenoid 25 to raise` the fitting orelement 22 to its upper limit of travel and` thus have the compressorcompletely unloaded.

Thus, no compression is provided and the refrigerant is merely drawninto the cylinder 10 through the port 19 and the passage made up of port2li, hollow interior 23, and notched portion 24, and discharged throughthe same passage. The cylinder now acts as a compressor in a completelyunloaded condition (i.e., with its capacity to pump reduced to zero). Ashort time after start-up, the time-delay switch 33 opens, breaking thesupply of electrical current to the solenoid 25, and the spring 26forces the tting 22 to the position shown. The compressor is thenloaded. Under the operation just discussed, the thermostatic switch 34is in the position in which refrigeration is called for. Should theswitch be in the alternative position, corresponding to no demand forrefrigeration, the solenoid will be continuously energized and thecylinder 10 will remain in an unloaded condition.

This invention provides a number of advantages over prior art structuresemployed for the same purposes. The invention here, when employed inconjunction with a compressor, does more than merely unload thecompressor, as was the case with prior art devices. Here, it is possibleto reduce the capacity of the compressor cylinder. In a multi-cylindercompressor, it is possible to reduce the capacity of all cylinders anequal amount. In contrast to this, many conventional unloading means forcylinders permit only complete unloading, one by one. This results inunequal torque and damages some drive means. Such a conventionalunloader is described in my prior Patent No. 2,761,616, issued September4, 1956. In contrast to this, the invention here permits a smoothreduction of capacity. Furthermore, in conventional systems, it is usualto unload all but 20430% of the cylinders in a multi-cylindercompressor, as to unload all of them would result in cessation of flowof gas and therefore of cylinder cooling. By keeping at least one or twocylinders cool by continuing their ow, it was hoped that the rest wouldbe cool also. In the inventive device, at least a minimum ow can beprovided for each cylinder through restricting the upward position ofthe element 22, irrespective of the number of cylinders, therebyattaining cooling of each.

It is to be appreciated that the flow member 22 can be positionedintermediate two adjoining cylinders, thus varying the capacity ofeachor a plurality of such members can be employed, each operating froma common shaft, so that each cylinder is unload to the same degree. In aform of invention where one port member as at 122 is slidably mounted inthe intake 115 common to both cylinders 110 and 210, a port member 122is positioned by means `of a connecting rod 129 connected to aneccentric 129a. For individual port members for each cylinder, the shaft129b to which the eccentric 129a is attached can be arranged in parallelto the crankshaft 212e instead of transverse, as shown. In this manner,each of a number of positioning rods such as 129 can be simultaneouslypositioned. The crankshaft 21251 is seen to be connected in conventionalfashion to the pistons 111 and 211 by means of piston rods 112 and 212,respectively.

The rod 129 is seen to be connected to a solid portion 122 of the member122, thev member 122 also having a hollow interior as at 123 andnotched-out portions as at 124 and 224, communicating, respectively,with the interior head spaces 110:1 and 210a of the cylinders 110 and210, respectively.

With the construction of FIG. 3, it will be seen that the sides of thepistons 111 and 211 contact the movable element 122 at all times inorder to keep it in position and to cooperate with the upper lip of thepistons 111 and 211 as they move up and down.

The embodiment of FIGS. 3-4 permits positioning of the flow element 122.This permits variation of the cornpressor loading. Normally, arefrigeration compressor, or, for that matter, most any compressor,operates at a fairly constant compression ratio and pressure level asload, speed, or both, vary. One of the features of the inventiveconstruction is that for a given capacity, i.e., compression ratio andpressure level, the time for gas to enter the cylinder is fairlyconstant. For example, at 18 r.p.s. and a 60 portion of the strokecorresponding to the port or notch 124 being open, the time the port isopen is 0.0093 of a second. At r.p.s. with the port being openthree-fourths of the stroke, i.e., 270, the time the port is open is0.0083 second.

As seen in FIG. 4, the element 122 has a pair of oppositely-disposed,arcuate side walls as at 122er and 222a, thereby providing portions ofthe cylinder walls. In the event it is desired to operate theconstruction of FIGS. 1 and 3 independently of the rods 29 and 129, theconstruction in FIG. 5 can be employed.

In FIG. 5, the numeral 310 designates generally the upper portion of thecylinder units wherein a flow element 322 is mounted for positionablemovement much the same as the element 122 in the showing in FIG. 3. Theintake is designated by the numeral 31S and connects to a suction lineas at 315a.

Provided as .an upward projection on the cylinder housing 310 is acasing 335 equipped with a bore 336 communicating with an annularchamber 337. The positionable element 322 is equipped with an integralannular ange as at 338 which is positioned within the chamber 337. Thecasing 335 is equipped with suitable seals as at 339 arranged to conformto the shape of the element 322 so as to seal Ithe refrigerant gascoming from the suction line 315:1 from the chamber 337 which is filledwith hydraulic uid.

The chamber 337 is defined in part by the wall 340 equipped with owports 341 `and 342. Overlying this portion of the wall 340 is asupplemental casing 343 which is equipped with an oil inlet as at 344and an aperture 34S through which a control knob 346 projects.Positioned about the control handle 346 is a exible seal 347 secured toa Valve .actuator 348. The actuator 348 is equipped with curved endswhich extend under a valve plate 349 as at 350 and 351.

Movement of the lever handle 346 upwardly in FIG. 5 results in raisingthe lower end of the valve plate 349 so that fluid is able to flow outof the upper end of chamber 337 into the supplemental casing chamber 352and then 'through the port 342 into the Ilower portion of the chamber337. This permits the element 322 to be moved upwardly under the jointinuence of gas pressure against the bottom as well as the frictionalengagement thereof by the pistons. When the desired position of theelement 322 has been achieved, the lever handle 346 is returned toneutral position, after which the lower end of the valve element 349covers the port 342 and serves yas a check valve.

Movement of the lever handle 346 downwardly results in the uncovering ofthe port 341, i.e., preventing the valve element 349 from serving as acheck valve so that uid issuing from the chamber 337 through the port342 into the supplemental casing chamber 352 is able to reenter thechamber 337 through the port 341. This results in a downward movement ofthe element 322 under the influence of suction and the frictionalengagement of the pistons with the element 322. A light spring pressuremay be applied by the spring 353 to provide the initial downwardmovement of the element 322 prior to the same becoming frictionallyengaged wi-th the pistons (not shown).

While, in the foregoing specification, a detailed description of theinvention has been given for clearness of understanding, those skilledin the Aart will perceive many variations in the details herein givenwithout departing from the spirit and scope of the invention.

I claim:

1. In a refrigeration apparatus, a pair of cylinders in side-by-siderelation, each having side and top walls dening a compression chamber, apiston mounted in each of said cylinders for reciprocal movementdefining intake and compression strokes, said Cylinders being equippedwith an opening in each of their side walls, means containingrefrigerant iuid communicating with said openings, an element positionedbetween said cylinders and IrlOLlIl-ifd in Said openings for movementtherein independent of the movement of said pistons, port means in saidcyli-nders for introducing and removing refrigerant lluid, and means forpositioning said element in said openings for changing the effectivearea of said openings and :to provide uid flow therethrough duringselected initial portions of each of the pistons compression strokes upto and including substantially all of the pistons compression strokes.

2. In a device of the character described, a pair of adjacent cylinderseach containing a piston for reciprocation therein, a crankshaft fordriving said pistons in outof-phase relationship, an opening in thecommon wall between said pair of cylinders, a movable element mountedwithin said opening and having its opposite sides shaped to lit closelyto said pistons when adjacent thereto, means for positioning saidelement within said opening to vary the effective size of said opening,and means in said element for owing fluid therethrough into saidcylinders.

3. In a gas compressor, a frame providing a cylinder cavity and anoutlet port for compressed refrigerant gas, an element movably mountedin said frame and having at least a segmental cylindrical wall toprovide at least a portion of the wall defining said cylinder cavity, apiston mounted in said cylinder cavity for reciprocal movement detiningintake and compression strokes, means for moving said piston and meansfor moving said element independent of said piston to change theeffective area of said cavity, said element containing a flow passagefor refrigerant gas communicating with said cylinder cavity.

4. The structure of claim 3 in which said means for moving said elementincludes a casing about said element and providing a hydraulic fluidchamber, a ange on said element projecting into said chamber to dividethe same into two portions, a llow passage communicating said portions,and selectively operable check valve means in said ow passage.

References Cited by the Examiner UNlTED STATES PATENTS 877,492 1/ 1908Doelling 230-25 1,481,358 1/1924 Dwyer 103-37 1,632,841 6/1927 Le Valley230-22 1,878,326 9/1932 Ricardo 230-22 2,004,474 6/1935 Schaer 230-212,011,864 8/1935 Lundh 103-37 2,041,422 5/1936 LOrange 103--37 2,041,4685/1936 Grubbs 103-37 2,501,054 3/1950 Huber 10S-173 2,524,235 10/1950Schenk 103--37 2,555,004 5/1951 Rinehart 23 0-30 2,555,005 5/ 1951Warneke 23 0-30 2,854,187 9/1958 Crooks 230-21 2,833,462 5/ 1958Scheerer 230-21 FOREIGN PATENTS 893,213 1/1944 France. 1,044,494 6/1953France.

622,780 12/ 1935 Germany.

742,768 12/1943 Germany.

403,180 12/1933 Great Britain.

Examiners.

G. M. THOMAS, W. I. KRAUSS, Assistant Examiners.

2. IN A DEVICE OF THE CHARACTER DESCRIBED, A PAIR OF ADJACENT CYLINDERSEACH CONTAINING A PISTON FOR RECIPROCATION THEREIN, A CRANKSHAFT FORDRIVING SAID PISTONS IN OUTOF-PHASE RELATIONSHIP, AN OPENING IN THECOMMON WALL BETWEEN SAID PAIR OF CYLINDERS, A MOVABLE ELEMENT MOUNTEDWITHIN SAID OPENING AND HAVING ITS OPPOSITE SIDES SHAPTED TO FIT CLOSELYTO SAID PISTONS WHEN ADJACENT THERETO, MEANS FOR POSITIONING SAIDELEMENT WITHIN SAID OPENING TO VARY THE EFFECTIVE SIZE OF SAID OPENING,AND MEANS IN SAID ELEMENT FOR FLOWING FLUID THERETHROUGH INTO SAIDCYLINDERS.